A sample of chromium was ionised by electron impact in a time of flight (TOF) mass spectrometer. Information from the mass spectrum about the isotopes of chromium in this sample is shown in Table 1.
Table 1 m/z50525354Abundance / %4.383.89.52.4\begin{array}{|c|c|c|c|c|} \hline \text{m/z} & 50 & 52 & 53 & 54 \\ \hline \text{Abundance / \%} & 4.3 & 83.8 & 9.5 & 2.4 \\ \hline \end{array}m/zAbundance / %504.35283.8539.5542.4
Calculate the relative atomic mass of chromium in this sample. Give your answer to one decimal place.
Write an equation, including state symbols, to show how an atom of chromium is ionised by electron impact, and give the m/zm/zm/z value of the chromium ion that would reach the detector first.
Calculate the mass, in kg, of one atom of 53Cr^{53}\text{Cr}53Cr. The Avogadro constant L=6.022×1023 mol−1L = 6.022 \times 10^{23}\ \text{mol}^{-1}L=6.022×1023 mol−1.
In a TOF mass spectrometer, the time of flight, ttt, of an ion is shown by the equation: t=dm2Et = d\sqrt{\frac{m}{2E}}t=d2Em In this equation, ddd is the length of the flight tube, mmm is the mass, in kg, of an ion and EEE is the kinetic energy of the ions. In this spectrometer, the kinetic energy of an ion in the flight tube is 1.150×10−13 J1.150 \times 10^{-13}\ \text{J}1.150×10−13 J. The time of flight of a 54Cr+^{54}\text{Cr}^+54Cr+ ion is 1.045×10−6 s1.045 \times 10^{-6}\ \text{s}1.045×10−6 s. Calculate the time of flight of the 50Cr+^{50}\text{Cr}^+50Cr+ ion. Give your answer to an appropriate number of significant figures.